This invention relates to a wireless transmitter, and more particularly, to a wireless transmitter used with a Keyless Entry System.
A Keyless Entry System (xe2x80x9cRKExe2x80x9d) allows a user to lock and unlock doors, sound a panic alarm, program seat and mirror positions, open a trunk, and/or perform other functions using a transmitter.
In Keyless Entry Systems, one or more unique identifying codes are programmed into the transmitter. In these Keyless Entry Systems, the transmitter and a receiver use a defined communication protocol. The communication protocol defines the timing of the bit stream and the tolerances. The transmitter can include a microprocessor that transmits according to a communication protocol. In some Keyless Entry Systems an external oscillator is required to provide a stable and accurate clock reference to the microprocessor. These oscillator circuits can comprise multiple parts that include an external crystal or an external resonator.
In some instances, multiple parts that include an external crystal or an external resonator, for example, can decrease the durability and increase the complexity, the size, the cost of manufacturing, and the cost of assembly of some Keyless Entry Systems. The increased cost of these Keyless Entry Systems can be especially high when large numbers of Keyless Entry Systems are manufactured and/or assembled.